JP2562972Y2 - Traction end structure of optical fiber cable - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tow end structure used for pulling and laying an optical fiber cable.

[0002]

2. Description of the Related Art Conventionally, in order to save labor for optical fiber cable connection work, a connector for connection is previously attached to the end of an optical fiber core of an optical fiber cable at a factory to protect the cable during storage and installation. For this reason, the ship is shipped with a towed end covered with a protective pipe, and a cable with the connector attached is towed locally and laid in a pipeline or the like.

[0003] As shown in a simplified view of Fig. 9, the internal structure of the towing end is mounted with the connector mounting positions dispersed in the longitudinal direction in order to prevent the connectors a ... from becoming bulky. A suitable number of fiber holders d and a connector holder e fixed at predetermined intervals to a tensile member c passing therethrough.
... hold the optical fiber cores f, and house the connectors a ... in the connector holder e.

[0004]

[Problems to be solved by the invention] However, in an ultra-multi-core optical fiber cable in which the number of optical fiber cores is as large as several thousand, the number of connectors to be attached is increased from hundreds to thousands. It is difficult to identify the numbers of the optical fiber core and the connector when holding or connecting the optical fiber to the holder, and the workability becomes extremely poor.

In the conventional optical fiber cable pulling end structure, when each connector is connected by a connection box or the like, an operation of disassembling the pulling end and taking out the connector causes the optical fiber core to be entangled with the optical fiber core. There was a problem of damaging the connector.

Accordingly, the present invention solves the above-mentioned conventional problems, and provides a towed end structure of an optical fiber cable in which the number of an optical fiber core and a connector can be easily identified and workability is improved. Aim.

[0007]

According to the present invention, there is provided a traction end structure in which a protective pipe is attached to an end of an optical fiber cable having a plurality of optical fiber cores. The optical fiber core wires are inserted into a plurality of flexible unit tubes while being divided into predetermined groups, and the unit is inserted into a plurality of tube holders juxtaposed at predetermined intervals in the longitudinal direction in the protective pipe. It holds the tube.

[0008]

According to this unit tube, even in a super multi-core optical fiber cable, the optical fiber cores are divided into predetermined groups, so that the optical fiber cores and the connectors are held and connected to the holder when the connector is held in the holder. The number of the connector can be easily identified.

Furthermore, even if the pulling end is disassembled and the connector is taken out, since the optical fiber core is held in the unit tube, it does not come apart and become entangled. Moreover, when the unit tube is provided inside the protective pipe, the distance between adjacent tube holders can be increased.

[0010] Further, even when a mechanical external force is applied during storage or laying of the optical fiber cable, the optical fiber core wire can be more reliably protected by the unit tube.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings showing embodiments.

FIGS. 1, 2 and 3 are half-cut views of the drawing end structure of the optical fiber cable according to the present invention divided into three parts. A protective pipe 4 is attached to the end of an optical fiber cable 2 having a plurality of optical fibers 1. When the cable 2 is pulled and laid in a pipeline or the like, the protective fiber 4 is attached to the tip of the optical fibers 1. The attached connection connectors 3 and the optical fibers 1 are protected.

The optical fiber cable 2 shown in FIG. 1 has an optical fiber ribbon 1 housed in a grooved spacer (not shown) and covered with an outer sheath (of a fiber unit) as a central tension. A multi-core unit-type optical fiber cable, in which a plurality of members are arranged around a member (tensile member), is illustrated.

Specifically, as shown in FIG. 1, the above-mentioned towing end is formed by exposing the base end of the towing line 5 passing through the center of the protective pipe 4 to the optical fiber cable 2 by peeling off the outer layer. The distal end of the tensile member 6 (cut to a predetermined length) is connected to the intermediate sleeve 7 via the connecting sleeve 8.

Numeral 9 denotes a spacer, which is mounted by caulking or the like on a holding fitting 10 attached to the distal end portion of the outer sheath layer of the optical fiber cable 2, and is provided inside the protective pipe 4 via O-rings 11, 11. 12 is sealing tape, 13 is washer, 14
Is a heat-shrinkable tube covering the end of the outer layer of the optical fiber cable 2.

Further, an end cap 15 is attached to the base end of the protection pipe 4 and holds the optical fiber cable 2. Reference numeral 16 denotes a protective tape wound around and fixed to the end cap 15, the protective pipe 4, and the optical fiber cable 2.

As shown in FIG. 3, a metal cap 17 is attached to the tip of the protection pipe 4 with an adhesive or the like, and the cap 17 and the protection pipe 4 are covered with a heat-shrinkable tube 18.

Inside the cap 17, a sleeve 19 with a male screw fixed to the tip of the traction wire 5 is fixed by a nut 21 via a small O-ring 20, and the tip of the sleeve 19 has An eye nut 22 for towing is installed.

Further, as shown in FIGS. 1, 2 and 3, a plurality of connector holders 23, fiber holders 24 and tube holders 25 are arranged in parallel in the longitudinal direction in the protective pipe 4. Specifically, the connector holders 23, the fiber holders 24, and the tube holders 25 are attached to the traction line 5 at predetermined intervals.

The connector holder 23 is a soft plastic molded product. As shown in FIG. 4, for example, as shown in FIG. 4, a cylindrical outer peripheral wall 26 having a predetermined thickness is provided, and an insertion hole 27 (through which the traction line 5 is inserted) is formed in the center. Are provided, and a plurality of plate-like holding walls 29 having a predetermined thickness are provided at predetermined intervals between the prism portions 28 and the outer peripheral wall 26 to form a plurality of connector storage cavities 30. It is formed. The connector storage chambers 30 are open in both axial directions, and the width dimension A of each connector storage chamber 30 is substantially equal.

The connector housing space 30 has a function of elastically holding and protecting the connector 3 and has a function of protecting the outer peripheral wall.
26 is cut out as appropriate, and for example, a hatched portion Y is cut open with a knife or scissors, so that it can be used as a fiber guide storage portion 31 for guiding the optical fiber cores 1.

As shown in FIG. 5, the fiber holder 24 has an arcuate groove-shaped holding portion 32 for guiding the optical fibers 1 and an insertion hole 33 for inserting the traction wire 5. The protection pipe 4 is made of a metal material or a hard resin in order to prevent deformation of the plastic protection pipe 4.

Further, as shown in FIG. 6, the tube holder 25 made of a metal such as an aluminum alloy has a U-shaped groove guide portion 35 for holding a unit tube 34 described later on the outer diameter side. And an insertion hole 36 for inserting the traction wire 5 is formed in the center.

The elongated tubular unit tube 34 is made of plastic or the like and has flexibility (see FIG. 2), and the optical fibers 1 are inserted and held in the unit tube 34. Has become. A slit 37 in the form of a cut is formed in the outer peripheral wall of the unit tube 34 in the longitudinal direction.
The optical fibers 1 are easily taken in and out.

As shown in FIG. 7, a plurality of optical fiber cores 1 that are exposed by peeling the outer layer of the optical fiber cable 2 are arranged in predetermined groups (for example, in the example of FIG. Unit tube divided into ───
Inserted at 34 ...

The length of the optical fibers 1 to which the connectors 3 are attached is changed sequentially for each predetermined group. As a result, the connectors 3 at the tips of all the optical fibers 1 of each group are mounted on the same connector holder 23 (as shown in FIG. 4).

As shown in FIG. 1, each of the fiber units 38 is held by a unit holder 39 attached to the strength member 6, and the optical fiber cores 1 exposed from the end of each of the fiber units 38 are Guided by a fiber guide 40.

Further, as shown in FIGS. 1, 2 and 6, the unit tubes 34 into which the optical fiber cores 1 are inserted in predetermined groups are respectively (twisted in the illustrated example).
It is held by the guide portions 35 of the tube holders 25.

Then, as shown in FIGS. 2, 3, and 4, the connectors 3...
Are elastically held in the connector storage chambers 30 of each connector holder 23 for each predetermined group, and a part of the outer peripheral wall 26 of the connector storage chambers 30 other than the connector storage chambers 30 holding the connectors 3. The optical fiber cores 1 of the other group, which are arranged so as to extend beyond the connector 3 and extend to the distal end thereof, are held as the fiber guide storage portion 31 by cutting out (as indicated by the oblique line Y in FIG. 4).

As shown in FIGS. 2, 3 and 5,
The holding portions 32 of the fiber holders 24 also appropriately hold the optical fiber cores 1 and wrap an adhesive tape or the like (not shown) to prevent the cores 1 from coming off.

Then, the eye nut 22 is pulled in the direction of the arrow to lay the optical fiber cable 2 (see FIG. 1) in a pipeline or the like.
. And the connector 3 are taken out and connected to the mating connector 3 indicated by a virtual line in FIG. 8 in a connection box such as a closure (not shown). At this time, the connectors 3 and 3 are kept connected by the clip 41.

According to the unit tube 34, even in the super-multi-core optical fiber cable 2, the optical fiber cores 1 are divided into a predetermined group.
Can be easily identified when the optical fiber cores 1 and the connectors 3 are held in the holder 25 or connected to the other party.

Furthermore, since the optical fiber cores 1 are held in the unit tube 34, the optical fiber cores 1 do not come apart and become entangled when the towing end is disassembled.

Further, even if a mechanical external force is applied when the optical fiber cable 2 is stored or laid, the optical fibers 1 can be more reliably protected by the unit tube 34. Moreover, when the unit tube 34 is provided inside the protective pipe 4, the interval between the adjacent tube holders 25 can be increased, and the number of tube holders 25 used can be reduced.

It should be noted that the present invention is not limited to the above-described embodiment, and the design can be freely changed without departing from the gist of the present invention.

For example, the number and the width dimension A of the connector storage chambers 30 of the connector holder 23 in FIG. 4 can be freely increased and decreased, and the connector storage chambers 30 can be freely formed in various directions other than the illustrated example. . Further, the shape and material of the tube holder 25 shown in FIG. 6 can be changed, and the number of the guide portions 35 can be freely increased or decreased. In addition, in the case of the optical fiber cable 2 having a slot configuration, it may be inserted into each tube 34 for each slot unit.

[0037]

[Effect of the Invention] The present invention is constructed as described above, and thus has the following remarkable effects.

Even when the number of the optical fiber cores 1 is as large as several thousand, the number of the optical fiber cores 1 and the connectors 3 is identified when the connectors 3 are connected. And the workability is greatly improved.

Further, when the towing end is disassembled, the optical fiber cores 1 and the connectors 3 are not damaged since the optical fiber cores 1 are not separated.

The unit tube 34 is connected to the protection pipe 4
In the case where the tube holders 25, 25 are arranged inside, the distance between the adjacent tube holders 25 can be increased, the number of the tube holders 25 to be used can be reduced, and the weight and cost can be reduced. Moreover, even if a mechanical external force is applied when the optical fiber cable 2 is stored or laid, the optical fibers 1 can be more reliably protected by the unit tube 34.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing a base end of an embodiment of the present invention.

FIG. 2 is a half sectional view showing the intermediate portion.

FIG. 3 is a half sectional view showing the tip.

FIG. 4 is a plan view of the connector holder.

FIG. 5 is a plan view of a fiber holder.

FIG. 6 is a plan view of a tube holder.

FIG. 7 is a simplified view of an end of an optical fiber cable.

FIG. 8 is a perspective view of the connector.

FIG. 9 is a simplified view showing the internal structure of a conventional towing end.

[Explanation of symbols]

 1 Optical fiber core 2 Optical fiber cable 4 Protection pipe 25 Tube holder 34 Unit tube

Claims (1)

(57) [Scope of request for utility model registration] An optical fiber cable having a plurality of optical fiber cores, wherein a protective pipe is attached to an end of the optical fiber cable, and the optical fiber core is inserted into a plurality of long and flexible unit tubes. A towed end structure for an optical fiber cable, wherein said unit tubes are held in a plurality of tube holders arranged in parallel in said protective pipe at predetermined intervals in a longitudinal direction in said protective pipe. .